(Meebook P78 Pro) Error communicating with device

[Gebb]

I currently have a Boyue Meebook P78 Pro, and I am having issues with connecting to Calibre. When I first got the device, it connected just fine. However, once I installed a micro sd card, the device will not work with Calibre. The sd card reads fine of the device itself. When I plug in my device, however, I get the error message "Error communicating with device." The output is pasted below. I also tried tried going to the debug device detection option, but all I get is

"calibre, version 5.39.0
ERROR: Device already detected: A device (Q78) is already detected by calibre. If you wish to debug the detection of another device, first disconnect this device."

The insturctions here said to have the device plugged in when choosing this option, so I am unsure what is happening. I am running an up to date version of Calibre. Any help would be greatly appreciated. Thank you.

calibre, version 5.39.0
ERROR: Error: Error communicating with device

C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:336:Failed to EnumObjects() of folder from device:[hr=0x80042009 wCode=7689] IDispatch error #7689: o15

Traceback (most recent call last):
File "calibre\gui2\device.py", line 87, in run
File "calibre\gui2\device.py", line 512, in _books
File "calibre\devices\mtp\driver.py", line 219, in books
File "calibre\devices\mtp\driver.py", line 191, in get_driveinfo
File "calibre\devices\mtp\windows\driver.py", line 271, in filesystem_cache
wpd.WPDError: C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:336:Failed to EnumObjects() of folder from device:[hr=0x80042009 wCode=7689] IDispatch error #7689: o15

[likebookstore]

does the problem fixed? if not, you can feedback to :meebook@haoqingtech.com

[jeffdonnelly]

FYI UPDATE (from thread: "Boyue Meebook P78 Pro not recognized by Calibre when uSD card present")
Ok, an info update after further work...

I tried again with another uSD card.

This time with a Sandisk Extreme PRO 128Gb Micro SDXC I V30 U3 formatted as exFAT.

The first try with this one had exact same results as before in Calibre, with a Comm error thrown. Also, the uSD card had all the directories written to the uSD card by the P78 Pro immediately upon insertion into the P78 Pro e-reader. I subsequently removed the uSD card, and via PC card reader deleted all the folders including the Android and Books folders.

I then recreated a new Books folder on the uSD card and ejected the uSD card from the PC reader and reinserted into the P78 Pro. Upon checking the uSD card after insertion into P78 Pro, I found that P78 Pro had again recreated the Movies, Music, and Photos folders, which i subsequently deleted while in the P78 Pro.

I then plugged the P78 Pro back into the PC running Calibre Portable, and both P78 Pro and the uSD card were recognized without errors. Subsequently, I tried moving books to uSD card via Calibre (Save to Device, Card A) and that also worked as expected. I really believe that having all those folders written to the uSD card upon insertion are causing issues (particularly the ANDROID folder), especially if their are hidden files being written i cannot see or access....

I now have a SanDisk 256GB Extreme microSDXC UHS-I uSD card on order.... It's very strange that the Samsung card will just not work correctly.

[jeffdonnelly]

Last Update:
okay, using a micro SD card from Samsung, an EVO Plus U3, 256Gb... a very fast card.

It seems that Calibre doesn't like the fact (it throws a comm error after reading the device after it's recognized and reads the P78 Pro and uSD card) that the Meebook P78 Pro writes a mirrored folder structure from the P78 Pro device to the external uSD card. The issue seems, specifically, to be the Android directory it writes to the uSD card.

...and P78 Pro won't let you delete the Android directory from the uSD card without removing it from the P78 Pro, so used a card reader on my PC to delete it, subsequently reinstalling it in the P79 Pro.

However, after reinserting the uSD card into the P78 Pro and rebooting it, the P78 Pro folder structure from the P78 Pro device is again placed onto the external uSD card... including the problematic Android folder (which is un-delete-able while in the P78 Pro).

Then decided to just eject the card while the P78 Pro still on, delete the Android folder from the uSD card via card reader/PC, and hot swap re-install the uSD card in the still running P78 Pro... whichi does NOT re-mirror the folder structure of the P78 Pro and Android folder. Calibre worked fine then...

BUT...

The next issue was, that the P78 Pro has 2 file manager "apps" that are either the standard for Android 11 system (i don't know the answer to that), or specific to the P78 Pro Android tablet e-reader. The apps are called, respectively, "Files"... and "File Manager".

Turns out even with Android folder deleted from uSD card on the PC and hot-swapped back into the P78 Pro with no Android folder present, if you subsequently run the "File Manager" app, the P78 Pro again re-mirrors the folder structure with the Android folder to the uSD card.

BUT - if you run the "FILES" app, it does NOT re-mirror the folder structure with the Android folder - but you have to ensure that the P78 Pro doesn't shut down for power saving, because upon rebooting from cold start, folder structure is mirrored to uSD card again.

Subsequently, i realized that even tho the system won't let you delete the Android folder on the uSD card, it WILL, for some reason allow you to RENAME it, and THEN it WILL let you delete the RENAMED Android folder while the uSD card it mounted in the running P78 Pro.....

I only wish i tried that earlier.... but, once i figure that out, before i connect the USB cable to the PC and Calibre, i ensure that either the Android folder ISN'T present on the uSD card - or if it is - I rename Android folder and then delete it.

THEN, Calibre works with out a hitch, with NO comm errors!